They will be available at:
domain.com/category/your-category/
This means that if view this URL you might also see posts (the built in WordPress ones) in there too as they too can have categories.
If you don’t want these ‘qna’ posts to be mixed in with the default posts then you should create a taxonomy and use that: i.e. advice-categories
Your advice posts will then be available at:
domain.com/advice-categories/your-advice-category/
You can specify your own slug too just like Custom post Types.